During extreme weather events spanning from heat waves to blizzards to floods, meteorologists often compare impressive temperature and precipitation values to “normal” to help put unusual weather events into perspective. But how exactly do scientists know the “normal” or “average” weather for any given location? Read on to find out.

Above image shows one of the many beautiful sunsets in New Jersey in August 2015

August started off hot with temperatures reaching the upper 80s to low 90s for the first four days of the month. By the 4th, severe weather broke out as a cold front traversed the Northeast with New England especially hard hit. In fact, a supercell or rotating thunderstorm pummeled through Massachusetts, producing 50 - 60mph wind gusts and golf ball sized hail stones.

Looking back at May 2015, many will remember the abundant dry, warm days and the first real taste of the upcoming summer. Not only did most of the major cities across the region rank May 2015 among the top five warmest on record, but a slew of bone dry days mixed with limited rain events helped place most of New England and North Jersey in a moderate drought. Let’s take a look back at this final month of climatological spring.